Treatment of wool to prepare it for manufacture



Dec. 18 1923. 11,478,20'3

T. A. COGHLAN TREATMENT OF WOOL TO PREPARE IT FOR MANUFACTURE Filed July 7, 1921 2 Sheets-Sheet 1 Dec, 18 1923. 1,4782% T. A. CQGHLAN TREATMENT OF WOOL TO PREPARE IT FOR MANUFACTURE Filed July 7, 1921 z'sheets-sheet 2 Patented Dec l8, 1923.

UNHTEID) STATES ane arena FFHQE.

TIMOTHY AUGUSTINE COGHLAN, OF LONDON, ENGI IAND;

TREATMENT OF wooI. To PREPARE IT FOR MAnUEAcTUaE.

Application filed Jul 7, 1921. Serial No. 432,949.

. for Manufacture, of which the following is a s ecification. R

ertain advantages presented by the use of trichlorethylene for extracting WOOl grease from wool, are known. I have dis-' covered another, namely that the condition of the woolwhich has. been treated with this solvent is such that when it is desirable that the wool should be treated by non-mechanical means for the removal of burrs or other vegetable matter embedded in the wool, the staple remains unafi'ected by the application of sulphuric acid, otherwise known as carbonising.

The objection which has hitherto militated. against the use of trichlorethylene has been the difficulty of recovering the solventleft in the wool, such recovery being essential both'for preventing injury to the workmen and for the economy of the process. Attempts to expel the solvent by means of hot air'have not been successful, partly because of the tendency of air in the presence of. moisture, which cannot Well be excluded, to oxidise trichlorethylene with formation'of hydrochloric acid, and partly because of the difliculty of condensing vapour of trichlorethylene when carried by a large volume of air. Steam has been suggested as a substitute for air but it is known to be inadvisable to expose wool to a'higher By my invention the trichlorethylene is expelled from the wool at a temperature of 45 C. or lower, by water, which has the' advantage that the wool is simultaneously washed, or by carbon dioxidefrom which, I find, it is far easier to condense tr1- chlorethylene vapour than it is to condense that vapour from air; as it is easy to obtain carbon dioxide'substantially free from air the trouble of possible oxidation disappears.

ommercial trichlorethylene of boiling point about 90 C. may be used. The action of the reagent on metals and on lubricants is such that certain precautions in the construction andarrangement of apparatus are necessary. For instance, its action on lead is such that this metalmust be avoided door which can be hermeticall have been used several times.

or in some wa protected, lest the colour of the wool be a ected. Againmvhere packed joints are required, greasy fabric and lead should preferably be avoided; or the action may be prevented by the interposition of an absorbent, for instance, between the vessel in which the vapour of the reagent is being generated and the exhauster, or the like.

A considerable economy is attained by the successive treatment of the wool in trichlorethylene that has already been used,

as this substance when warmed to say 40 C.

willtake up three or more times its volume V in wool grease, but' the final operation should be done with clean trichlorethylene.

In one form of the process the wool to be treated either in its original condition or more or less opened up, is charged into a cage which is ,run on wheels or slid into a vessel, preferably a cylinder having its axis horizontal and one end formed as a sealed. Otherwise the cage may be lowere' into the treatment vessel from above, in which case the top or open side should be appropriately faced to form an hermetic closure with a lift-away or hinged cover having means for fastening it when closed. This vessel having been evacuated of air as far as practicable, trichlorethylene is run into it and is heated in the vessel by steam coils or the like to a temperature of about 45 C. The reagent first applied to the raw wool may For the sake of illustration it is assumed that the trichlorethylene has been used twice. After remaining in the chamber for ,a period of fifteen (15) minutes less or more according to the condition of the .wool, the trichlorethylene is run into a storage tank for thrice used liquid, or directly into a still, for the recovery of thereagent and the grease. Its place in the vessel is now taken by tI'lChIOI". ethylene which has been used once before, which is heated to the said temperature and then run into the storage tank for twice Finally,

the wool in t secend and so on, in order that there may always-be a vessel being discharged and another being charged.

Tn another form where large quantities of wool .have to be treated the trichlorethylene is introduced into the first of a sense of connected vessels charged with wool which havebeen evacuated of air as far as practicable, and after standing a short time-is allowed to enter a second chamber, preferably at the bottom, and to pass out of that chamber into the third chamber, and so on until it passes throu h-the whole series of chambers entering eac at the bottom and bein drawn off at the top. When i8 first chamber has been deprivedof its grease, or is considered to be sufic'iently treated, that chamber is disconnected from the flow of trichlorethylene and the wool in the vessel dealt with as hereinafter described. v

When the wool has been removed the vessel is again charged, evacuated of air to -the required extent and connected with the last vessel of the series. After the first vessel has been disconnected,- further tri-- chlorethylene is admitted to the second vesgel passing through the whole series as beore.

' has been sufficiently treated the flow to that vessel is shut 0E and the same course followed as in the case of the-first vessel. Each, vessel is dealt with in turn so that the final treatment of the wool is made-with unused 'trichlorethylene. When every vessel of the series has been dealt with, or whenever considered convenient, the used trichlorethylene will be passed through a still and condenser, for the recovery of the reagent from the ethylene W111 be collected in a storage tank, suitably placed.

In ordinary use each vessel would contam the quantity of greasy wool in an ordinary bale, about 380.1bs. When diflerent classes of wool are bein treated and it is not desirable to mix t em, smaller ves- 'sels may be used; but for general pur oses,

. the economic size of a vessel'would v to contain 380 to 440 lbs. 1

' This system is illustrated in the accompanying diagram Fig. 1 which .shows the state of affairs when the second vessel in the series has become the first to receive fresh solvent. l

\1, 2, 3, 4 represent the vessels (there may be a much larger number) each nearly filled with wool and all connected through respective valves (1 with the vacuum-pump attached to pipe e. Valve (1 is in the position for flow of solvent from overhead tank f to pipe 9, and valve 0 is open-to admit solvent into the vessel 2. After the necessary sojourn (about fifteen minutes) of the solvent in vessel 2, valve 0 is closedand When the wool in the second vessel ease. The recovered trichlornavaaoa valve 6 is turned into the position shown, there being a vacuum in vessel 3 and pipe h extending to the bottom of vessel 2, the presuntil the solvent is sufliciently saturated with grease. In the meantime vessel 1 has been recharged with wool and evacuated, so that when valve 5 has been turned into the position shown and valve d into the position for connecting pipes k and Z, the solvent flows as before from vessel 4 to vessel 1, now the last in the series. From here it may be re-circulated through the system, but generally it is sufiiciently saturated with grease; valve 7) is therefore turned into the position shown so that the solvent may flow as before through pipe at into the storage tank or still n which may be connected with the vacuum pump through a suitable pipe not shown in Fig. 1. From the pipe connections indicated it will be seen that each vessel is capable of being the first or the last to receive solvent as the case may be. The functions ofvalves b, 0 a will be apparent from the above description.

' Fig. 2 shows an elevation and Fig. 3 a plan of a plant constructed to operate on this system.

The vessels 1, 2, 3,, 4 are adapted to receive the wheeled cages containing the .wool which run on rails '0. Each vessel is adapted to be heated by an internal steam coil.

The vacuum pump p serves both for exhaust same letters as those used with reference to Fig. 1 have the functions already explained.

The residual trichlorethylene contained in the treated wool may be recovered before the wool. is removed either by the use of hot Water or of carbon diox1de. In the first case hot water is run into the vessel, a temperature of about 45". C. being maintained under a partial vacuum while the vessel is open to a condenser ;whereby the residual.

reagent is recovered. Afterwards this water is run .oif, preferably through a heat inter changer, and is either worked up for potash saltsor run to waste. j

Instead of'hot water the treated wool may be subjected to a current of carbon dioxide which may; be preheated to such temperature as may be necessary, but always so that the temperature of the wool does not exceed 45 C. The current becomes saturated I with trichlorethyle'ne vapours; it thence is passedthrough a condenser, roperly cooled and; made to bubble throng '011 in. suitfor potash salts,

at/egos ably arranged tank; the trichlorethylene will be absorbedby the oil while the carbon dioxide goes to the gas holder from which it reverts to the process. This system of treatment by carbon dioxide is valuable in places where the use of water'is riot desired; if water is available, hot water may be run into the vessel for the purpose of'carrying OK the potash salts held by the wool. Afterwards, this water is run off preferably through a heat interchanger and worked up should that be considered desirable."

' The wool, after being removed from the chamber, will be practically free from grease and potash salts, nevertheless, it may with advantage be washed or rinsed in clean water to free it from sand or other mineral table substance will still remain. The wool may now be dried by any of the known methods, after which it will be ready to undergo treatment to prepare it for the processes of manufacture, and will be in the condition indicated in paragraph 3 hereof. If recourse is necessary to carbonising, it will be found that the treatment of wool according to this process enables the fibre to withstandthe action of sulphuric acid without the loss sustained under all of the processes of preparation now in practical use. 93

Having thus described the nature of the said invention and thebest means I know of carrying the same into practical efiect, I claim A. process of preparing wool for 'manufacture, whiclTconsists in charging the wool into a series of connected vessels, then successively charging each vessel with trichlorethylene and discharging the trichlorethylene, then charging each vessel with carbon dioxide at a temperature not exceeding t5 (3. and collecting and condensing the trichlorethylene thus expelled from the wool.

In testimony .whereof I have signed my name to this specification.

TIMOTHY AUGUSTINE OOGHLAN.

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